Hydraulic device for transmitting movement



Jan. 23, 1940. R. SENSAUD DE LAVAUD ,1 7,

HYDRAULIC DEVICE FOR TRANSMITTING MOVEMENT Filed April 22, 1935' sSheets-Sheet 1 mvsm'on zPoaserJzwanuo a: darn/a.

I M W? W ATTORN 5Y5 1949- R. SENSAUD DE LAVAUD 2l87s937 HYERAULIC DEVICEFOR TRANSMITTING MOVEMENT Filed April 22, 193-5 3 Sheets-Sheet 2 i Imvsu roe Poaa-ErJE/vsnuo pal/M400.

AT'I'OR N EYS Jan; 23, 1940; R. SENSAUD DE V D 2,187,937

HYDRAULIC 'DEVICE FOR TRANSMITTING MOVEMENT Filed April 22, 1953 sSheet-Sheet a Y n m g .P m x 2 1 W A K 4 w M m 2 .m \4 n e 3M 7 1 5mm, 4W w u M mww Em fi-om En o.

Inventor EOBEET Saws/v00 aEZ/n/Aua.

flliomeys Patented Jan. 23, 1940 HYDRAULIC nEvIoE FOR-TRANSMITTINGMOVEMENT I Robert S'ensaud de Lavaud, Paris, France, assignor to DimitriSensaud De Lavaud, Paris, France In France April 23,- 1932 ApplicationApril 22, 1933, Serial No. 667,408

2 Claims.

The invention aims to provide certain improvements by which hydraulicdevices for transmitting movement are made to operate smoothly andefficiently and with a minimum of friction and by which other advantagesare secured as stated in detail hereinafter.

The improved device is particularly adapted as a transmission forautomobiles, being applicable to other uses also. The transmissionincludes an hydraulic pump, referred to herein generally as a pump, anda receiver referred to herein generally as a turbine, and certaindevices for automatically controlling their action and reaction on eachother.

The accompanying drawings illustrate embodiments of the invention.

Fig. 1 is the left end, and Fig. 1a the right end, of a longitudinalsection (partly in elevation) of the complete apparatus;

20 Fig. 2 is a longitudinal section of the outer portion of the pump,turbine and adjacent parts, illustrating a modification;

Fig. 3 is a diagram in a developed horizontal section showing the vanesof the pump and of the turbine and of the intermediate redirecting orcontrolling device arranged between the turbine outlet and the pumpinlet;

Fig. 4 is a similar view of a modification in which the redirecting orcontrolling device is located between the pump outlet and the turbineinlet;

Fig. 5 is a similar view of the particular arrangement corresponding toFig. 1; in which the redirecting means is between the turbine outlet andthe pump inlet. i v

Fig. 6 is a cross-section of a spring connection and free wheelingassembly for the redirector.

The pump is fixedly connected to the motor shaft or driving shaft. Theturbine is fixed to a driven shaft which is co-axial with the drivinposition or may be free to rotate with the pump andthe turbine.

The drawings illustrate the casing or shell I of a centrifugal pumpcarrying vanes 5 and bolted to a plate 2 which in turn is bolted to thedriving shaft .3. The arrow I shows the point of entry 65 and directionofthe oil into the pump. Fig.5

The redirector may be is a section at approximately the point ofentrance and shows the inclination of the vanes 5 (which inclination maybe varied as shown in modifications referred to hereinafter).

The turbine has a shell 4 with vanes 6 in- 5 clined for example asillustrated in Fig. 5. The shell of the turbine is riveted to a flange 4of a tube 4 which is rotatably mounted on bearings 4 carried by atubular extension 4* from the plate 2. The part 4 is keyed to a sleeve 110 having at its right-hand end a ring of internal, claws 8 and a ringof external gear teeth 9. The turbine, therefore, rotates the sleeve 1which may be clutched directly to the driven shaft or connected to thelatter for reverse rotation.

The vanes of the pump may be fixed as illustrated or other known orsuitable constructions may be used The casing ofthe pump acts as afiy-wheel. By fixing the vanes directly thereon there is economy ofconstruction and also a lessened friction as compared with designs inwhich the complete coupling is arranged to rotate in a separate casing.The casing of one of the rotary devices, the shell of the pump in theconstruction illustrated, forms the fluid-tight housing of the parts.

Between the entry to the vanes 5 of the pump and the exit from the vanes6 of the turbine, are disposed the vanes of a redirector Ill. Each ofthese vanes is made of two parts, a fixed part H situated at the pumpentry side, and a part I! at the opposite side which is movable about apivot pin [3 which is normal to the wall of the redirector.

The parts ii are moved by the oil against an elastic resistance, suchthat the restoring; effort is substantially proportional to the momentof the force which is applied to the vanes or movable parts [2. For thispurpose, Figs. 1 and 5 show the movable end of the part l2 carrying alug I4 which lies in a groove l5 which lies in a plane approximatelyparallel to the axis of the I main shaft and is formed in the peripheryof a drum l8 which has a tubular portion l6 fitting freely into anannular recess in a ring I! which carries the body ill of the redirectorand which formsa member of a free-wheeling assembly the other parts ofwhich are the rollers I 8 and the ring 19 keyed to the sleeve 20 whichis integral with the external shell 2| in which the unit is carried. Theinner surface of the ring I! is so shaped, as shownin Fig. 6, as to 7enable it to rotate freely in one direction but to lock the rollers I8between the rings H and I9 and prevent the ring I! from rotating in theop- 1 ing devices 22 (springs for example) which tend to press the partIE to the right in Fig. 5, with relation to the part l0, and to hold themovable parts l2 of the vanes in the full line position shown. The forceof the springs is proportional at any instant to that of the oil on themovable parts of the vanes A tight joint 23 is provided between theinner portions of the shells of the pump and the turbine, so that atight enclosure for the vanes of the redirector is obtained.

The connection between the rotatingmembers and the fixed parts is madetight by the use of floating joints. Oil leaking out of these joints iscaught in chambers which are not under pressure and which are in turnbrought into communication with the chamber or spaces which are in-communication with the suction end of the pump, with an adjustableoutlet valve, hereinafter referred to, between the discharge from thechambers not under pressure and the suction end of the pump.

The 'fixed tubular part 20 carries a floating joint ring 24 around theoutside of which is a tubular extension 26 which is rigidly and tightlyfastened to the shell I of the pump, and which in turn rotates within apacking ring 26" carried by the shell of a receptacle 25 formed in thispart of the outer casing 2|. Any oil escaping from the pump enclosurepasses into the chamber 25 and out of the bottom of it through a pipe49.

Within the sleeve 1 is a sliding shaft 21 which at its right-hand end issplined to a surrounding hollow driven shaft 28 by means of a key 29.This shaft 21 has a ring of claws 3| adapted to co-operate with theclaws 8 in the sleeve 1 (which driving shaft. The shaft 21 is shown inthe g by means of an adjustable valve.

neutral position. .It may be shifted to the right to connect it with thesleeve 1 and the turbine,

or to the left to connect it with the part 4 and the driving shaft. Theshaft 21 is guided at its left'end by a bearing ring 34 engaging theinterior of the sleeve 1.

The shifting of the sliding shaft is effected by means of a lever 35(Fig. 1a) having a spherical pivot 36 held in place by a packing 31. Theinner end of the lever carries a fork 38 which engages and shifts theshaft 21 in the usual way}. The chamber 39 in -which-the.fork is locatedis subjected to the pressure of the oil. Its wall 40 is arranged to makean oil-tight connection around the driven shaft 28 by means of afloating ring 4|. escaping-from the chamber 39 and also (through thepipe 49) any oil escaping from the chamber 25.

In the lower part of the chamber42 a pump 43 (of the gear type forexample) draws the oil from the bottom of the chamber 42 by way of aport 42 and forces it through a port 42 back into the chamber 39. Thepump may be driven by any suitable means, such for example, as wormgears of which one, 44, .is keyed on the shaft 44 of the pump, and theother, 28, is keyed on the driven shaft 28.

The pressure within the chamber 39 is limited A passage 45 between thelower ends of the chambers 39 and The chamber 42 will receive any oiland pressure recuperator and the floating joints described, the oilcontained within the device is maintained under proper pressure so as tocompensate for leakage and to prevent any c.-.-vitation or voids in thebody of oil supplied to the driving pump l.

The sliding shaft 21 has a central axial bore 51 open at the left endand communicating at the right end with a capillary passage 58 leadingfrom the center of the shaft within the space of the suction chamber 42.Any air in the center of the system will thus be drawn through the bore51 and expelled by centrifugal force into the chamber 42 from which itcan escape after dcpositing in said chamber any'small quantities of oilwhich it may carry.

A planetary gearing and braking system is provided. On the left end ofthe driven shaft 28 is the planetary or differential gearing whichconnects it with the sleeve 1 which is rotated by the turbine. On theend of the shaft 28 there is fixed a drum 50 which has internal gearteeth 5| located in the same plane as the external gear teeth 9 on thesleeve 1. Between these two gears are pinions 52 meshing with the gearsand mounted idly on their shafts 53 which are arranged in a ring in thelateral face of a spider with a flange 54 constituting a brake drum.Surrounding this is a brake jaw 55 which may be actuated by the usualbrake pedal. The central part of the spider is extended axially to forma sleeve 56 mounted to rotate on the sleeve 1.

The mode of operation is as follows:-

The sliding shaft 21 is assumed to be in the intermediate position inwhich neither of the two rows of claws is in engagement. If the drivingshaft 3 starts under the action of the motor for example, it rotates thepump I and the fluid is actuated by centrifugal force and displacesitself 'in the direction of the arrow f through the vanes of the pump.It then passes into the vanes of the turbine 4. The wings of theredirector guide the fluid at exit from the vanes of the turbine to sendit back into the vanes of the pump, thus flowing in a closed cycle. Inthis movement, owing to the shape of the vanes shown diagrammatically inFig. 5, it is seen that the turbine 4 is rotated in the same directionas the pump I. At the instant when the speeds of rotation of the pumpand the turbine become the same, the oil flows in reduced volume oroutput, and the redirector l0 finds itself driven in the same directionas the turbine 4 and the pump I through the rings '1 and I9 and therollers It.

On starting, the residual speed of the fluid at exit from the wings ofthe turbine 4 is a maximum and this fluid acts on the movable part I2 ofthe wings of the redirector H! which yields to the shock and takes upthe position shown in dotted lines in Fig. 5. The sleeve l6 turnsrelatively to the sleeve l1 of the redirector against the resistance ofthe elastic restoring devices 22. This movement is shown by comparisonbetween the full line and the dotted line positions of the part l2 inFig. 5.

As the speed of the turbine 4 increases, the exit speed of the fluidlessens as well as the thrust sleeve, the drum 54 carrying their shaftsbeing idle, and the driven shaft remains at rest. If the claws 8 of thesleeve 1 are engaged with the claws 3| of the sliding shaft 21, it isseen that the driven shaft 28 is thus rotatedin the same direction asthe driving shaft.

The driven shaft having reached the speed of the driving shaft, at thisinstant, the sliding shaft 21 may be shifted'to the left and its claws32 type of Fig. 1 or of that of Fig. 2) may be fixedengaged with theclaws 33 of the driving shaft, thus causing the driven shaft 28 to bedirectly driven.

By restoring the sliding shaft 21 to the intermediate position where therows of claws 3| and 32 are no longer in engagement,'and operating thepedal actuating the jaw 55 of the brake, the speed of the drum 54carrying the shafts of the planet pinions 52 is reduced and the drivenshaft 2g is driven in the opposite direction to the driv- Thedistributor or redirector lllmay, as illustrated in Fig. 2, be providedwith two rows of vanes II and li the former located between the turbineexit and the pump inlet, and the latter between the pump exit and theturbine inlet.

The vanes of the distributor (whether of the In Fig. 3 there isillustrated a distributor In with vanes l2 each of which is pivoted to afixed point at one end and has at the opposite end a pin I4 entering aslot I5 in the part I!) which .is rotatable relatively to the part Itwhich carries the fixed pivot. The arrangement of Fig. 3 is illustratedin a design suitable to be placed at the entry to the vanes of the pump,like the design of Fig. 5. But the same principle of vanes entirelymovable may be applied to a redirector at the opposite end of the pump.

Fig. 4 shows the use of fixed vanes II and illustrates a design for aredirector placed at the exit end' of the pump vanes. But the sameprinciple of fixed vanes in the redirector may be applied to one placedat the opposite end.

It has been previously proposed to use a concentric centrifugalpump-turbine combination as an hydraulic coupling or transmissionbetween a motor and receiver. Where a single turbine has been used ithas generally had the same angular speed as the pump. Different speedshave been provided in the case of two turbines in series with fixedguides between them. With all of these known combinations, as far as Iam aware, it has been possible'to increase the moment of the force onthe turbine, when the load on itis increased, without also increasingthe moment of the driving force applied to the pump, the increased loadbeing compensated by a reduction speed of the'turbine. But'thisreduction in speed of the turbine is accompanied by losses in theefliciency with which the pressure is transmitted through the system.

With the present invention such losses of efficiency are avoided. Whenthe moment of the force applied to the turbine increases to take care ofan increased load, the regulator modifies the relation of the forceswithin the combination so that theefliciency remains as great aspossible and so that 'the motor which drives the pump can remain under aconstant or only slightly variable load. In explanation of this, I haveindicated the triangles of forces in Fig. 3 (entry to pump and exitfromturbine) and in Fig.4 2

(exit from pump and entry to turbine).

The effective moment of the force applied to the pump is the moment atthe exit minus that at the entry; each moment, of course, being theoutput of oil passing the point in question, multiplied by thetangential component of its velocity and by the radius of the pump atthat point. The force is proportional to the speed of the flow.

Therefore, if the speed of the pump itself at this point is u (Fig. 4)and absolute exit speed of oil from the pump is C, the tangential speedof the oil is Cu' This multiplied by the exit radius (which we call rgives us 011. 1 as the measure of the exit moment, which has to bemultiplied by the weight or output of oil at any instant, to determinethe moment of the forces at this point.

Similarly at the pump entrance, u (Fig. 3) is the speed of thepump'itself, C the absolute entrance speed of the oil and Cu thetangential entrance speed of the oil. This multiplied by the radius (r')gives us Cu'r as the measure of the moment of the force with which theoil enters.

Therefore, thenet moment for the pump is the volume or output of oilmultiplied by the difference between Cu r and C'ur'.

Similarly the moment of the forces on the turbine is proportional to thedifference between the moments of the forces acting at the entrance andexit respectively of the turbine. If at the entrance to the turbine(Fig. 4) the speed of the turbine itself is u and the speed of the fluidis C the tangential entrance speed of the fluid is Cu This multiplied bythe radius (r at this point gives the moment of the force is 021 2Similarly for the exit from the turbine, we have the turbine speed a(Fig. 3), the absolute speed of the fluid 0 and the component orprojection thereof C11 This multiplied by the radius (1"*) gives us themoment at this point Cu r And .the

- radii remain constant, we can secure this result by varying therelation between the quantities Cu and Cu, which represent thetangential projections of the exit speed and entrance speed respectivelyof the oil into and out of the pump. This may be' done in three ways:

. 1. Cu must increase, or V 2. Cu must decrease, or

3. Both these changes must take place.

(C') and the tangential line U.

Furthermore, the moment of the forces on the turbine being necessarilydifferent from that on the pump, and the pump and turbine beingconcentric with each other, the stream of fluid going through the vanesofthe redirector will impress on the latter a moment equal to thedifference between the moments of the pump and turbine respectively.This may be effected by arranging the redirector in any one of thethreeways stated, namely, between the turbine exit and the pump entry, Fig.3; or between the pump exit and the turbine entry, Fig. 4; or in bothlocations, Fig. 2.

I. The quantity Cu, (Fig. 3) depends on the angle a between thedirection of exit of the oil The vanes I2 change the direction of flowof the oil passing from the turbine to the pump and can be set todecrease the angle a. and thus to increase the tangential componentthereof, Cu.

By making the vanes l2 movable, as illustrated in Fig. 3, there is anacceleration or a diminution of the quantity Cu as the flow of oil isincreased or diminished. The minimum effect is shown in full lines. Whenthe fiow of the oil increases it presses the pivoted ends 0 to the leftso that the vanes assume the dotted line position, the pins l4 in thefree ends of the vanes sliding in the slots I5 In the dotted lineposition, the direction of escape of the oil is such as to make asmaller angle a and to increase the quantity Cu.

II. For a diminution of the quantity Cu at the exit of the pump, Fig. 4,we assume that the speed of the pump M2 is constant. If Cu is to be lessthan 1L2, that is, if the tangential velocity of the oil is to be-lessthan the velocity of the pump itself, the vanes 5 must be inclinedbackward so that the projection 5 thereof makes an angle 12 greater than90 degrees with the tangential line.

At the same time, the quantity Cu at the turbine entrance must increasebecause we are as' suming an increased force on the turbine. Therefore,we must have the vanes 6 l of the redirector set at such an angle as todirect the flow into the turbine along a line C which makes an angle a.with a tangential line less than 90 degrees, and so much less as tosecure the necessary length of the tangential component Cu. The quantityC which-represents the speed of arrival of the oil at the turbine(andthe tangential component Cu thereof) will be increasedproportionately to the quantity of oil. The angle 0. may also be made tovary, diminishing as the quantity increases, by making the vanes limovable under the pressure of the flowing oil. I

Thus we get the desired effect by placing the redirector between thepump exit and turbine entry in connection with a pump with the free endsof its vanes at such an angle that their extension 5 makes an anglegreater than 90 degrees with the tangential advance of the turbine. Thepump vanes may have their exit ends fixed as shown, or maybe of otherknown or suitable constructions.

III. For an increase of the quantity Cu and a simultaneous decrease ofthe quantity Cu, it is only necessary to use a redirector of the generalcharacter shown in Fig. 21 withyanes at both points, an outer ring ofvanes ll? between the pumpoutlet and the turbine inlet and an inner ringof vanes ll between the turbine outlet and the pump inlet; using theangular dispositions of the vanes previously described at the respectivelocations.

It is also to be noted that as the shell of the redirector is heldfixed, the speed of the turbine will increase beyond that of the pump itthe moment of the load on the turbine falls below that of the pump. Inthat case the system works as an automatic accelerator; as well as anautomatic speed reducing device when the load on the turbine increases.In reality, the turbine then becomes the counterpart of a real serieselectric motor which tends of its own accord to work at constant power.This is due merely to the pressing of the guide vanes between the exitfrom the turbine and the entry into the pump, for example.

If it is not desired to take advantage of the property of acceleratingthe speed as above, and if, further, it is desired to decrease thelosses which correspond to that system, the shell of the redirector willbe mounted to rotate, as by means of the free wheel l8, but will beheldfast as long as the moment of forces on the turbine is greater thanthat on the pump and will be released as soon as the moment on theturbine tends to become smaller. As soon as this tendency occurs, theredirector is not subjected to any substantial rotary forces and thewhole combination functions as a simple coupling.

What I claim as my invention and desire to secure by Letters Patent is:

1. An hydraulic transmission including in combination two devices,namely, a rotary pump, a turbine operated by the fluid discharged fromthe pump and arranged to return the fluid to the pump, and a redirectorbetween said two devices, the pump, the turbine and the redirector beingco-axial with one another and the redirector having vanes which changethe direction of the fluid in its passage from one to the other of saiddevices, the opposite ends of the redirector vanes being pivotallymounted on a pair of adjacent rings with one of said pivots movableaxially with respect to its ring, said rings being held in startingangular position by yielding means between them, which permit the vanesto be moved to different angles under the thrust of the fluid.

2. A hydraulic transmission comprising in combination a pump havingimpelling blades in fixed position thereon, a turbine having impelledblades in fixed position thereon, and a redirector between each group ofpump and turbine blades, said. redirector blades being pivoted to varytheir inclination to fluid passing between said turbine and pump blades,means automatically to vary the position of said redirector blades withchanges in the relative speed of said pump and turbine, the blades ofsaid redirector being continuous from the leading to the following edgeto form continuous unbroken paths for fluid between said pump andturbine blades.

ROBERT SENSAUD DE LAVAUD.

